by David Jackson, USA TODAY

by David Jackson, USA TODAY

COLUMBIA, S.C. â?? Here's one of the safest bets in American politics: Incumbent Sen. Lindsey Graham will win the most votes when South Carolina Republicans hold their primary on June 10.

The question is whether Graham will get more than 50%, thereby avoiding a risky runoff.

No fewer than six Tea Party-type Republicans are challenging Graham in the primary, trying to get themselves into a one-on-one showdown with the incumbent senator that would theoretically take place June 24.

In terms of simple math, the size of the Republican field makes it harder for Graham to win the 50% he'll need to avoid a runoff. But the sheer density of the field has made it difficult for any of the little-known challengers to break out of the pack.

"Is anybody going to get traction? Who knows?" said former South Carolina Republican chair Barry Wynn, who has given money to Graham over the years. "If anybody does get traction, that means a runoff, and a runoff could mean vulnerability."

Graham, in a telephone interview, said he is confident, but is taking nothing for granted.

"I feel good about getting over 50%," he said. "We're there â?? we just need to stay there."

In a series of meetings with Republican and Tea Party groups, Graham's challengers offer similar critiques: The two-term senator, who also served six years in the U.S. House, has become too much a creature of Washington; he has lost touch with Republicans in South Carolina, and is too willing to truck with Democrats on issues like spending and immigration.

Graham said that "it's a challenging time for any incumbent" because "Washington is clearly broken." He described himself as a conservative willing to work with the other side to solve problems, whether it's the federal debt or national security.

â?¢ Det Bowers, a Columbia pastor who has emerged as the best-funded of Graham's challengers. Bowers says his experience as a lawyer, minister and business person give him the background necessary to understand the challenges faced by everyday South Carolinians.

Bowers â?? who has the endorsement of RedState editor and conservative commentator Erick Erickson â?? said Graham's support "becomes more tenuous the more people learn about his record."

â?¢ Nancy Mace, a Charleston business owner and the first female graduate of the Citadel, who said in a television ad that "we cannot change Washington until we change who we send to Washington."

â?¢ Lee Bright, a state senator from Spartanburg who notes he is the only Graham challenger who has actually held elected office. Bright say Graham "just doesn't represent South Carolina," and â?? like other opponents â?? he criticizes Graham for voting in favor of President Obama's two Supreme Court nominees, Sonia Sotomayor and Elena Kagan.

â?¢ Richard Cash, a businessman from Anderson County who narrowly lost a runoff for a House seat in 2010 now held by Rep. Jeff Duncan, R-S.C. Cash says Graham has "Potomac disease" and notes his state approval rating has been under 50%.

â?¢ Bill Connor, an attorney and Army reservist from Orangeburg, noted that "I'm the only person who's run statewide," losing a GOP runoff for lieutenant governor in 2010.

â?¢ Benjamin Dunn, a Columbia attorney who criticizes what he called Graham's apparent willingness to get involved in the Syria conflict.

Graham has agreed to debate his six opponents â?? but not until June 7, just three days before the vote.

Whoever wins the Republican nomination will likely be favored in the November election in this very GOP state.

Many of Graham's opponents have criticized him for what they call excessive bipartisanship, citing his work with Democrats on such issues as immigration, the budget and court appointments.

When Senate Democrats voted to change the rules on nominee confirmations by ending filibusters, Bright said that Graham's "appeasement approach" has "proven to be a failure."

Graham said senators have to work with others to get things done and accomplish conservative goals. "I embrace being a problem solver," he said.

While the GOP challengers try to get ahead of each other, and within striking distance of Graham, the incumbent is working to wrap up the nomination in the June 10 primary â?? and has been working for years.

Money may be his biggest advantage. Graham has up to $7 million to spend, dwarfing his opponents in total. He has been a steady presence on television and radio in the Palmetto State.

Organizationally, the Graham campaign cites 176 campaign county chairs and 5,221 precinct captains in all 46 South Carolina counties.

Before a meeting of Richland County Republicans at a barbecue restaurant in Columbia, retired educator Mary Cobb wouldn't say who she plans to vote for. But she cited Graham's resources and visibility as reasons why he is the favorite.

"He's got the money," Cobb said. "And he's spending it."

Graham has also worked hard to win support, or at least a lack of opposition, from establishment Republicans in South Carolina. No "big name" Republicans, including the state's U.S. House members, decided to challenge him, despite the rumblings of the Tea Party and other critics.

Even if one of his opponents pushes Graham into a runoff, he or she would face a big challenge: That contest would take place only two weeks after the primary, not giving the challenger much time to mount a new offensive.

Graham said that South Carolina voters need to keep the national picture in mind. In recent years, he said, Republicans have lost winnable Senate races by nominating bad candidates, and this time around party members "don't want to put seats at risk."

Citing his opponents, Graham said, "It's up to them to prove that they can withstand the scrutiny" of a high-profile election.